1 files changed, 37 insertions, 0 deletions
diff --git a/target/linux/bcm27xx/patches-5.15/950-0897-drm-vc4-plane-Prevent-async-update-if-we-don-t-have-.patch b/target/linux/bcm27xx/patches-5.15/950-0897-drm-vc4-plane-Prevent-async-update-if-we-don-t-have-.patch
new file mode 100644
index 0000000000..a6d539ecdf
--- /dev/null
+++ b/target/linux/bcm27xx/patches-5.15/950-0897-drm-vc4-plane-Prevent-async-update-if-we-don-t-have-.patch
@@ -0,0 +1,37 @@
+From d04c74e3f30be64b0e14d7ed2b6088f91ac6ea64 Mon Sep 17 00:00:00 2001
+From: Maxime Ripard <maxime@cerno.tech>
+Date: Wed, 16 Mar 2022 16:44:45 +0100
+Subject: [PATCH] drm/vc4: plane: Prevent async update if we don't have
+ a dlist
+
+The vc4 planes are setup in hardware by creating a hardware descriptor
+in a dedicated RAM. As part of the process to setup a plane in KMS, we
+thus need to allocate some part of that dedicated RAM to store our
+descriptor there.
+
+The async update path will just reuse the descriptor already allocated
+for that plane and will modify it directly in RAM to match whatever has
+been asked for.
+
+In order to do that, it will compare the descriptor for the old plane
+state and the new plane state, will make sure they fit in the same size,
+and check that only the position or buffer address have changed.
+
+Signed-off-by: Maxime Ripard <maxime@cerno.tech>
+---
+ drivers/gpu/drm/vc4/vc4_plane.c | 4 ++++
+ 1 file changed, 4 insertions(+)
+
+--- a/drivers/gpu/drm/vc4/vc4_plane.c
++++ b/drivers/gpu/drm/vc4/vc4_plane.c
+@@ -1429,6 +1429,10 @@ static int vc4_plane_atomic_async_check(
+ 
+ 	old_vc4_state = to_vc4_plane_state(plane->state);
+ 	new_vc4_state = to_vc4_plane_state(new_plane_state);
++
++	if (!new_vc4_state->hw_dlist)
++		return -EINVAL;
++
+ 	if (old_vc4_state->dlist_count != new_vc4_state->dlist_count ||
+ 	    old_vc4_state->pos0_offset != new_vc4_state->pos0_offset ||
+ 	    old_vc4_state->pos2_offset != new_vc4_state->pos2_offset ||